Q60. In vivo gene therapy differs from ex vivo therapy because genetic material is:
[UPSC NDA — Practice]
- (a) Only used in dead cells
- (b) Never carried by vectors
- (c) Always transferred into plants
- (d) Delivered directly into the patient’s tissues
Answer: (d) Delivered directly into the patient’s tissues
Explanation: In vivo therapy delivers genetic material or editing machinery directly into the body, using methods such as viral vectors or nanoparticles. Ex vivo therapy modifies collected cells before returning them. Each approach has distinct challenges of targeting and safety.
Q59. Which cells are modified in standard CAR-T cell therapy?
[State PSC — Practice]
- (a) Platelets
- (b) Osteoclasts only
- (c) T lymphocytes
- (d) Mature red blood cells
Answer: (c) T lymphocytes
Explanation: Chimeric antigen receptor T-cell therapy engineers a patient’s or donor’s T lymphocytes to recognise selected cell-surface targets. It has transformed treatment of certain blood cancers. Potential adverse effects include cytokine-release syndrome and neurological complications.
Q58. Monoclonal antibodies are populations of antibodies that typically:
[UPSC CSE — Practice]
- (a) Are produced only in plants
- (b) Recognise the same specific epitope
- (c) Have randomly unrelated binding sites
- (d) Contain no protein
Answer: (b) Recognise the same specific epitope
Explanation: Monoclonal antibodies arise from a single antibody-producing cell lineage or engineered equivalent. They target a defined antigenic epitope and are used in diagnostics and medicine. Their specificity distinguishes them from broad mixtures of polyclonal antibodies.
Q57. The term transcriptome denotes which collection?
[UPSC CSE (Pre) 2016]
- (a) All RNA transcripts expressed under specified conditions
- (b) Every protein of an organism
- (c) The entire set of chromosomes in mitosis
- (d) The complete DNA sequence only
Answer: (a) All RNA transcripts expressed under specified conditions
Explanation: The transcriptome is the total collection of RNA transcripts expressed by a cell, tissue or organism in a defined condition. Unlike the genome, expression patterns can change with developmental stage, cell type, disease and environmental signals.
Q56. Hybridoma technology usually combines which two cell types?
[WBCS — Practice]
- (a) Red blood cell and platelet
- (b) Neuron and pollen grain
- (c) Skin cell and chloroplast
- (d) Antibody-producing B cell and immortal myeloma cell
Answer: (d) Antibody-producing B cell and immortal myeloma cell
Explanation: A hybridoma is formed by fusing a selected antibody-producing B lymphocyte with an immortal myeloma cell. The resulting clone can secrete a specific antibody continuously. This technology made large-scale monoclonal antibody production possible.
Q55. A recombinant subunit vaccine usually contains:
[MPPSC — Practice]
- (a) A transplanted human chromosome
- (b) Only an antibiotic
- (c) A selected pathogen antigen produced by recombinant methods
- (d) The complete infectious pathogen in every case
Answer: (c) A selected pathogen antigen produced by recombinant methods
Explanation: Recombinant subunit vaccines expose the immune system to selected antigens, often proteins produced in engineered cells. They do not necessarily contain live pathogens. Because isolated antigens may stimulate weaker responses, formulation and adjuvants are important.
Q54. Recombinant hepatitis B vaccine is produced using genetically engineered cells that express:
[UPPCS — Practice]
- (a) Rabies virus genome in full
- (b) Hepatitis B surface antigen
- (c) Human haemoglobin
- (d) Bacterial cellulose
Answer: (b) Hepatitis B surface antigen
Explanation: Many hepatitis B vaccines contain recombinant hepatitis B surface antigen made in expression hosts such as yeast. The purified antigen stimulates protective immunity without requiring live hepatitis B virus in the vaccine preparation.
Q53. Which structure is especially common as a vector in bacterial genetic engineering?
[UPPCS (Pre) 2015]
- (a) Plasmid
- (b) Lysosome
- (c) Plastid
- (d) Ribosome
Answer: (a) Plasmid
Explanation: Plasmids are small, generally circular extrachromosomal DNA molecules that can replicate independently in bacteria. Engineered plasmids carry origins of replication, selectable markers and insertion sites, allowing researchers to introduce and amplify genes within appropriate host cells.
Q52. Which genetic material is delivered by an mRNA vaccine to instruct cells to make an antigen?
[RAS / RPSC — Practice]
- (a) Only a preformed antibody
- (b) Purified starch
- (c) An intact human chromosome
- (d) Messenger RNA
Answer: (d) Messenger RNA
Explanation: Messenger-RNA vaccines introduce RNA instructions that host cells translate into an antigen. Lipid nanoparticles commonly protect and deliver the RNA. The mRNA does not need to enter the nucleus or alter chromosomal DNA to produce an immune response.
Q51. A viral vector differs from a naked DNA fragment because the vector:
[SSC CGL — Practice]
- (a) Cannot enter any cell
- (b) Contains no nucleic acid
- (c) Uses engineered virus-associated delivery mechanisms
- (d) Must always cause the original disease
Answer: (c) Uses engineered virus-associated delivery mechanisms
Explanation: Viral vectors exploit the ability of viruses to deliver nucleic acids into cells. Vectors are engineered to limit unwanted replication or pathology while carrying useful genetic instructions. Targeting, immune response and insertional risks depend on the chosen vector.
